2 * dcssblk.c -- the S/390 block driver for dcss memory
4 * Authors: Carsten Otte, Stefan Weinhuber, Gerald Schaefer
7 #define KMSG_COMPONENT "dcssblk"
8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10 #include <linux/module.h>
11 #include <linux/moduleparam.h>
12 #include <linux/ctype.h>
13 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/blkdev.h>
17 #include <linux/completion.h>
18 #include <linux/interrupt.h>
19 #include <linux/platform_device.h>
20 #include <linux/pfn_t.h>
21 #include <linux/dax.h>
22 #include <asm/extmem.h>
25 #define DCSSBLK_NAME "dcssblk"
26 #define DCSSBLK_MINORS_PER_DISK 1
27 #define DCSSBLK_PARM_LEN 400
28 #define DCSS_BUS_ID_SIZE 20
30 static int dcssblk_open(struct block_device
*bdev
, fmode_t mode
);
31 static void dcssblk_release(struct gendisk
*disk
, fmode_t mode
);
32 static blk_qc_t
dcssblk_make_request(struct request_queue
*q
,
34 static long dcssblk_blk_direct_access(struct block_device
*bdev
, sector_t secnum
,
35 void **kaddr
, pfn_t
*pfn
, long size
);
36 static long dcssblk_dax_direct_access(struct dax_device
*dax_dev
, pgoff_t pgoff
,
37 long nr_pages
, void **kaddr
, pfn_t
*pfn
);
39 static char dcssblk_segments
[DCSSBLK_PARM_LEN
] = "\0";
41 static int dcssblk_major
;
42 static const struct block_device_operations dcssblk_devops
= {
45 .release
= dcssblk_release
,
46 .direct_access
= dcssblk_blk_direct_access
,
49 static const struct dax_operations dcssblk_dax_ops
= {
50 .direct_access
= dcssblk_dax_direct_access
,
53 struct dcssblk_dev_info
{
56 char segment_name
[DCSS_BUS_ID_SIZE
];
62 unsigned char save_pending
;
63 unsigned char is_shared
;
64 struct request_queue
*dcssblk_queue
;
66 struct list_head seg_list
;
67 struct dax_device
*dax_dev
;
72 char segment_name
[DCSS_BUS_ID_SIZE
];
78 static ssize_t
dcssblk_add_store(struct device
* dev
, struct device_attribute
*attr
, const char * buf
,
80 static ssize_t
dcssblk_remove_store(struct device
* dev
, struct device_attribute
*attr
, const char * buf
,
83 static DEVICE_ATTR(add
, S_IWUSR
, NULL
, dcssblk_add_store
);
84 static DEVICE_ATTR(remove
, S_IWUSR
, NULL
, dcssblk_remove_store
);
86 static struct device
*dcssblk_root_dev
;
88 static LIST_HEAD(dcssblk_devices
);
89 static struct rw_semaphore dcssblk_devices_sem
;
92 * release function for segment device.
95 dcssblk_release_segment(struct device
*dev
)
97 struct dcssblk_dev_info
*dev_info
;
98 struct segment_info
*entry
, *temp
;
100 dev_info
= container_of(dev
, struct dcssblk_dev_info
, dev
);
101 list_for_each_entry_safe(entry
, temp
, &dev_info
->seg_list
, lh
) {
102 list_del(&entry
->lh
);
106 module_put(THIS_MODULE
);
110 * get a minor number. needs to be called with
111 * down_write(&dcssblk_devices_sem) and the
112 * device needs to be enqueued before the semaphore is
116 dcssblk_assign_free_minor(struct dcssblk_dev_info
*dev_info
)
119 struct dcssblk_dev_info
*entry
;
121 if (dev_info
== NULL
)
123 for (minor
= 0; minor
< (1<<MINORBITS
); minor
++) {
125 // test if minor available
126 list_for_each_entry(entry
, &dcssblk_devices
, lh
)
127 if (minor
== entry
->gd
->first_minor
)
129 if (!found
) break; // got unused minor
133 dev_info
->gd
->first_minor
= minor
;
138 * get the struct dcssblk_dev_info from dcssblk_devices
139 * for the given name.
140 * down_read(&dcssblk_devices_sem) must be held.
142 static struct dcssblk_dev_info
*
143 dcssblk_get_device_by_name(char *name
)
145 struct dcssblk_dev_info
*entry
;
147 list_for_each_entry(entry
, &dcssblk_devices
, lh
) {
148 if (!strcmp(name
, entry
->segment_name
)) {
156 * get the struct segment_info from seg_list
157 * for the given name.
158 * down_read(&dcssblk_devices_sem) must be held.
160 static struct segment_info
*
161 dcssblk_get_segment_by_name(char *name
)
163 struct dcssblk_dev_info
*dev_info
;
164 struct segment_info
*entry
;
166 list_for_each_entry(dev_info
, &dcssblk_devices
, lh
) {
167 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
168 if (!strcmp(name
, entry
->segment_name
))
176 * get the highest address of the multi-segment block.
179 dcssblk_find_highest_addr(struct dcssblk_dev_info
*dev_info
)
181 unsigned long highest_addr
;
182 struct segment_info
*entry
;
185 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
186 if (highest_addr
< entry
->end
)
187 highest_addr
= entry
->end
;
193 * get the lowest address of the multi-segment block.
196 dcssblk_find_lowest_addr(struct dcssblk_dev_info
*dev_info
)
199 unsigned long lowest_addr
;
200 struct segment_info
*entry
;
204 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
205 if (set_first
== 0) {
206 lowest_addr
= entry
->start
;
209 if (lowest_addr
> entry
->start
)
210 lowest_addr
= entry
->start
;
217 * Check continuity of segments.
220 dcssblk_is_continuous(struct dcssblk_dev_info
*dev_info
)
223 struct segment_info
*sort_list
, *entry
, temp
;
225 if (dev_info
->num_of_segments
<= 1)
229 sizeof(struct segment_info
) * dev_info
->num_of_segments
,
231 if (sort_list
== NULL
)
234 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
235 memcpy(&sort_list
[i
], entry
, sizeof(struct segment_info
));
240 for (i
= 0; i
< dev_info
->num_of_segments
; i
++)
241 for (j
= 0; j
< dev_info
->num_of_segments
; j
++)
242 if (sort_list
[j
].start
> sort_list
[i
].start
) {
243 memcpy(&temp
, &sort_list
[i
],
244 sizeof(struct segment_info
));
245 memcpy(&sort_list
[i
], &sort_list
[j
],
246 sizeof(struct segment_info
));
247 memcpy(&sort_list
[j
], &temp
,
248 sizeof(struct segment_info
));
251 /* check continuity */
252 for (i
= 0; i
< dev_info
->num_of_segments
- 1; i
++) {
253 if ((sort_list
[i
].end
+ 1) != sort_list
[i
+1].start
) {
254 pr_err("Adjacent DCSSs %s and %s are not "
255 "contiguous\n", sort_list
[i
].segment_name
,
256 sort_list
[i
+1].segment_name
);
260 /* EN and EW are allowed in a block device */
261 if (sort_list
[i
].segment_type
!= sort_list
[i
+1].segment_type
) {
262 if (!(sort_list
[i
].segment_type
& SEGMENT_EXCLUSIVE
) ||
263 (sort_list
[i
].segment_type
== SEG_TYPE_ER
) ||
264 !(sort_list
[i
+1].segment_type
&
265 SEGMENT_EXCLUSIVE
) ||
266 (sort_list
[i
+1].segment_type
== SEG_TYPE_ER
)) {
267 pr_err("DCSS %s and DCSS %s have "
268 "incompatible types\n",
269 sort_list
[i
].segment_name
,
270 sort_list
[i
+1].segment_name
);
286 dcssblk_load_segment(char *name
, struct segment_info
**seg_info
)
290 /* already loaded? */
291 down_read(&dcssblk_devices_sem
);
292 *seg_info
= dcssblk_get_segment_by_name(name
);
293 up_read(&dcssblk_devices_sem
);
294 if (*seg_info
!= NULL
)
297 /* get a struct segment_info */
298 *seg_info
= kzalloc(sizeof(struct segment_info
), GFP_KERNEL
);
299 if (*seg_info
== NULL
)
302 strcpy((*seg_info
)->segment_name
, name
);
304 /* load the segment */
305 rc
= segment_load(name
, SEGMENT_SHARED
,
306 &(*seg_info
)->start
, &(*seg_info
)->end
);
308 segment_warning(rc
, (*seg_info
)->segment_name
);
311 INIT_LIST_HEAD(&(*seg_info
)->lh
);
312 (*seg_info
)->segment_type
= rc
;
318 * device attribute for switching shared/nonshared (exclusive)
319 * operation (show + store)
322 dcssblk_shared_show(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
324 struct dcssblk_dev_info
*dev_info
;
326 dev_info
= container_of(dev
, struct dcssblk_dev_info
, dev
);
327 return sprintf(buf
, dev_info
->is_shared
? "1\n" : "0\n");
331 dcssblk_shared_store(struct device
*dev
, struct device_attribute
*attr
, const char *inbuf
, size_t count
)
333 struct dcssblk_dev_info
*dev_info
;
334 struct segment_info
*entry
, *temp
;
337 if ((count
> 1) && (inbuf
[1] != '\n') && (inbuf
[1] != '\0'))
339 down_write(&dcssblk_devices_sem
);
340 dev_info
= container_of(dev
, struct dcssblk_dev_info
, dev
);
341 if (atomic_read(&dev_info
->use_count
)) {
345 if (inbuf
[0] == '1') {
346 /* reload segments in shared mode */
347 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
348 rc
= segment_modify_shared(entry
->segment_name
,
351 BUG_ON(rc
== -EINVAL
);
356 dev_info
->is_shared
= 1;
357 switch (dev_info
->segment_type
) {
361 set_disk_ro(dev_info
->gd
, 1);
363 } else if (inbuf
[0] == '0') {
364 /* reload segments in exclusive mode */
365 if (dev_info
->segment_type
== SEG_TYPE_SC
) {
366 pr_err("DCSS %s is of type SC and cannot be "
367 "loaded as exclusive-writable\n",
368 dev_info
->segment_name
);
372 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
373 rc
= segment_modify_shared(entry
->segment_name
,
376 BUG_ON(rc
== -EINVAL
);
381 dev_info
->is_shared
= 0;
382 set_disk_ro(dev_info
->gd
, 0);
391 pr_err("DCSS device %s is removed after a failed access mode "
392 "change\n", dev_info
->segment_name
);
394 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
396 segment_unload(entry
->segment_name
);
398 list_del(&dev_info
->lh
);
400 kill_dax(dev_info
->dax_dev
);
401 put_dax(dev_info
->dax_dev
);
402 del_gendisk(dev_info
->gd
);
403 blk_cleanup_queue(dev_info
->dcssblk_queue
);
404 dev_info
->gd
->queue
= NULL
;
405 put_disk(dev_info
->gd
);
406 up_write(&dcssblk_devices_sem
);
408 if (device_remove_file_self(dev
, attr
)) {
409 device_unregister(dev
);
414 up_write(&dcssblk_devices_sem
);
417 static DEVICE_ATTR(shared
, S_IWUSR
| S_IRUSR
, dcssblk_shared_show
,
418 dcssblk_shared_store
);
421 * device attribute for save operation on current copy
422 * of the segment. If the segment is busy, saving will
423 * become pending until it gets released, which can be
424 * undone by storing a non-true value to this entry.
428 dcssblk_save_show(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
430 struct dcssblk_dev_info
*dev_info
;
432 dev_info
= container_of(dev
, struct dcssblk_dev_info
, dev
);
433 return sprintf(buf
, dev_info
->save_pending
? "1\n" : "0\n");
437 dcssblk_save_store(struct device
*dev
, struct device_attribute
*attr
, const char *inbuf
, size_t count
)
439 struct dcssblk_dev_info
*dev_info
;
440 struct segment_info
*entry
;
442 if ((count
> 1) && (inbuf
[1] != '\n') && (inbuf
[1] != '\0'))
444 dev_info
= container_of(dev
, struct dcssblk_dev_info
, dev
);
446 down_write(&dcssblk_devices_sem
);
447 if (inbuf
[0] == '1') {
448 if (atomic_read(&dev_info
->use_count
) == 0) {
449 // device is idle => we save immediately
450 pr_info("All DCSSs that map to device %s are "
451 "saved\n", dev_info
->segment_name
);
452 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
453 if (entry
->segment_type
== SEG_TYPE_EN
||
454 entry
->segment_type
== SEG_TYPE_SN
)
455 pr_warn("DCSS %s is of type SN or EN"
456 " and cannot be saved\n",
457 entry
->segment_name
);
459 segment_save(entry
->segment_name
);
462 // device is busy => we save it when it becomes
463 // idle in dcssblk_release
464 pr_info("Device %s is in use, its DCSSs will be "
465 "saved when it becomes idle\n",
466 dev_info
->segment_name
);
467 dev_info
->save_pending
= 1;
469 } else if (inbuf
[0] == '0') {
470 if (dev_info
->save_pending
) {
471 // device is busy & the user wants to undo his save
473 dev_info
->save_pending
= 0;
474 pr_info("A pending save request for device %s "
475 "has been canceled\n",
476 dev_info
->segment_name
);
479 up_write(&dcssblk_devices_sem
);
482 up_write(&dcssblk_devices_sem
);
485 static DEVICE_ATTR(save
, S_IWUSR
| S_IRUSR
, dcssblk_save_show
,
489 * device attribute for showing all segments in a device
492 dcssblk_seglist_show(struct device
*dev
, struct device_attribute
*attr
,
497 struct dcssblk_dev_info
*dev_info
;
498 struct segment_info
*entry
;
500 down_read(&dcssblk_devices_sem
);
501 dev_info
= container_of(dev
, struct dcssblk_dev_info
, dev
);
504 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
505 strcpy(&buf
[i
], entry
->segment_name
);
506 i
+= strlen(entry
->segment_name
);
510 up_read(&dcssblk_devices_sem
);
513 static DEVICE_ATTR(seglist
, S_IRUSR
, dcssblk_seglist_show
, NULL
);
515 static struct attribute
*dcssblk_dev_attrs
[] = {
516 &dev_attr_shared
.attr
,
518 &dev_attr_seglist
.attr
,
521 static struct attribute_group dcssblk_dev_attr_group
= {
522 .attrs
= dcssblk_dev_attrs
,
524 static const struct attribute_group
*dcssblk_dev_attr_groups
[] = {
525 &dcssblk_dev_attr_group
,
530 * device attribute for adding devices
533 dcssblk_add_store(struct device
*dev
, struct device_attribute
*attr
, const char *buf
, size_t count
)
535 int rc
, i
, j
, num_of_segments
;
536 struct dcssblk_dev_info
*dev_info
;
537 struct segment_info
*seg_info
, *temp
;
539 unsigned long seg_byte_size
;
543 if (dev
!= dcssblk_root_dev
) {
547 if ((count
< 1) || (buf
[0] == '\0') || (buf
[0] == '\n')) {
552 local_buf
= kmalloc(count
+ 1, GFP_KERNEL
);
553 if (local_buf
== NULL
) {
562 for (i
= 0; (i
< count
&& (buf
[i
] != '\0') && (buf
[i
] != '\n')); i
++) {
563 for (j
= i
; j
< count
&&
566 (buf
[j
] != '\n'); j
++) {
567 local_buf
[j
-i
] = toupper(buf
[j
]);
569 local_buf
[j
-i
] = '\0';
570 if (((j
- i
) == 0) || ((j
- i
) > 8)) {
575 rc
= dcssblk_load_segment(local_buf
, &seg_info
);
579 * get a struct dcssblk_dev_info
581 if (num_of_segments
== 0) {
582 dev_info
= kzalloc(sizeof(struct dcssblk_dev_info
),
584 if (dev_info
== NULL
) {
588 strcpy(dev_info
->segment_name
, local_buf
);
589 dev_info
->segment_type
= seg_info
->segment_type
;
590 INIT_LIST_HEAD(&dev_info
->seg_list
);
592 list_add_tail(&seg_info
->lh
, &dev_info
->seg_list
);
596 if ((buf
[j
] == '\0') || (buf
[j
] == '\n'))
600 /* no trailing colon at the end of the input */
601 if ((i
> 0) && (buf
[i
-1] == ':')) {
605 strlcpy(local_buf
, buf
, i
+ 1);
606 dev_info
->num_of_segments
= num_of_segments
;
607 rc
= dcssblk_is_continuous(dev_info
);
611 dev_info
->start
= dcssblk_find_lowest_addr(dev_info
);
612 dev_info
->end
= dcssblk_find_highest_addr(dev_info
);
614 dev_set_name(&dev_info
->dev
, "%s", dev_info
->segment_name
);
615 dev_info
->dev
.release
= dcssblk_release_segment
;
616 dev_info
->dev
.groups
= dcssblk_dev_attr_groups
;
617 INIT_LIST_HEAD(&dev_info
->lh
);
618 dev_info
->gd
= alloc_disk(DCSSBLK_MINORS_PER_DISK
);
619 if (dev_info
->gd
== NULL
) {
623 dev_info
->gd
->major
= dcssblk_major
;
624 dev_info
->gd
->fops
= &dcssblk_devops
;
625 dev_info
->dcssblk_queue
= blk_alloc_queue(GFP_KERNEL
);
626 dev_info
->gd
->queue
= dev_info
->dcssblk_queue
;
627 dev_info
->gd
->private_data
= dev_info
;
628 blk_queue_make_request(dev_info
->dcssblk_queue
, dcssblk_make_request
);
629 blk_queue_logical_block_size(dev_info
->dcssblk_queue
, 4096);
630 queue_flag_set_unlocked(QUEUE_FLAG_DAX
, dev_info
->dcssblk_queue
);
632 seg_byte_size
= (dev_info
->end
- dev_info
->start
+ 1);
633 set_capacity(dev_info
->gd
, seg_byte_size
>> 9); // size in sectors
634 pr_info("Loaded %s with total size %lu bytes and capacity %lu "
635 "sectors\n", local_buf
, seg_byte_size
, seg_byte_size
>> 9);
637 dev_info
->save_pending
= 0;
638 dev_info
->is_shared
= 1;
639 dev_info
->dev
.parent
= dcssblk_root_dev
;
642 *get minor, add to list
644 down_write(&dcssblk_devices_sem
);
645 if (dcssblk_get_segment_by_name(local_buf
)) {
649 rc
= dcssblk_assign_free_minor(dev_info
);
652 sprintf(dev_info
->gd
->disk_name
, "dcssblk%d",
653 dev_info
->gd
->first_minor
);
654 list_add_tail(&dev_info
->lh
, &dcssblk_devices
);
656 if (!try_module_get(THIS_MODULE
)) {
661 * register the device
663 rc
= device_register(&dev_info
->dev
);
667 dev_info
->dax_dev
= alloc_dax(dev_info
, dev_info
->gd
->disk_name
,
669 if (!dev_info
->dax_dev
) {
674 get_device(&dev_info
->dev
);
675 device_add_disk(&dev_info
->dev
, dev_info
->gd
);
677 switch (dev_info
->segment_type
) {
681 set_disk_ro(dev_info
->gd
,1);
684 set_disk_ro(dev_info
->gd
,0);
687 up_write(&dcssblk_devices_sem
);
692 list_del(&dev_info
->lh
);
693 blk_cleanup_queue(dev_info
->dcssblk_queue
);
694 dev_info
->gd
->queue
= NULL
;
695 put_disk(dev_info
->gd
);
696 list_for_each_entry(seg_info
, &dev_info
->seg_list
, lh
) {
697 segment_unload(seg_info
->segment_name
);
699 put_device(&dev_info
->dev
);
700 up_write(&dcssblk_devices_sem
);
703 list_del(&dev_info
->lh
);
705 blk_cleanup_queue(dev_info
->dcssblk_queue
);
706 dev_info
->gd
->queue
= NULL
;
707 put_disk(dev_info
->gd
);
708 up_write(&dcssblk_devices_sem
);
710 if (dev_info
== NULL
)
712 list_for_each_entry_safe(seg_info
, temp
, &dev_info
->seg_list
, lh
) {
713 list_del(&seg_info
->lh
);
714 segment_unload(seg_info
->segment_name
);
725 * device attribute for removing devices
728 dcssblk_remove_store(struct device
*dev
, struct device_attribute
*attr
, const char *buf
, size_t count
)
730 struct dcssblk_dev_info
*dev_info
;
731 struct segment_info
*entry
;
735 if (dev
!= dcssblk_root_dev
) {
738 local_buf
= kmalloc(count
+ 1, GFP_KERNEL
);
739 if (local_buf
== NULL
) {
745 for (i
= 0; (i
< count
&& (*(buf
+i
)!='\0') && (*(buf
+i
)!='\n')); i
++) {
746 local_buf
[i
] = toupper(buf
[i
]);
749 if ((i
== 0) || (i
> 8)) {
754 down_write(&dcssblk_devices_sem
);
755 dev_info
= dcssblk_get_device_by_name(local_buf
);
756 if (dev_info
== NULL
) {
757 up_write(&dcssblk_devices_sem
);
758 pr_warn("Device %s cannot be removed because it is not a known device\n",
763 if (atomic_read(&dev_info
->use_count
) != 0) {
764 up_write(&dcssblk_devices_sem
);
765 pr_warn("Device %s cannot be removed while it is in use\n",
771 list_del(&dev_info
->lh
);
772 kill_dax(dev_info
->dax_dev
);
773 put_dax(dev_info
->dax_dev
);
774 del_gendisk(dev_info
->gd
);
775 blk_cleanup_queue(dev_info
->dcssblk_queue
);
776 dev_info
->gd
->queue
= NULL
;
777 put_disk(dev_info
->gd
);
779 /* unload all related segments */
780 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
)
781 segment_unload(entry
->segment_name
);
783 up_write(&dcssblk_devices_sem
);
785 device_unregister(&dev_info
->dev
);
786 put_device(&dev_info
->dev
);
795 dcssblk_open(struct block_device
*bdev
, fmode_t mode
)
797 struct dcssblk_dev_info
*dev_info
;
800 dev_info
= bdev
->bd_disk
->private_data
;
801 if (NULL
== dev_info
) {
805 atomic_inc(&dev_info
->use_count
);
806 bdev
->bd_block_size
= 4096;
813 dcssblk_release(struct gendisk
*disk
, fmode_t mode
)
815 struct dcssblk_dev_info
*dev_info
= disk
->private_data
;
816 struct segment_info
*entry
;
822 down_write(&dcssblk_devices_sem
);
823 if (atomic_dec_and_test(&dev_info
->use_count
)
824 && (dev_info
->save_pending
)) {
825 pr_info("Device %s has become idle and is being saved "
826 "now\n", dev_info
->segment_name
);
827 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
828 if (entry
->segment_type
== SEG_TYPE_EN
||
829 entry
->segment_type
== SEG_TYPE_SN
)
830 pr_warn("DCSS %s is of type SN or EN and cannot"
831 " be saved\n", entry
->segment_name
);
833 segment_save(entry
->segment_name
);
835 dev_info
->save_pending
= 0;
837 up_write(&dcssblk_devices_sem
);
841 dcssblk_make_request(struct request_queue
*q
, struct bio
*bio
)
843 struct dcssblk_dev_info
*dev_info
;
845 struct bvec_iter iter
;
847 unsigned long page_addr
;
848 unsigned long source_addr
;
849 unsigned long bytes_done
;
851 blk_queue_split(q
, &bio
, q
->bio_split
);
854 dev_info
= bio
->bi_bdev
->bd_disk
->private_data
;
855 if (dev_info
== NULL
)
857 if ((bio
->bi_iter
.bi_sector
& 7) != 0 ||
858 (bio
->bi_iter
.bi_size
& 4095) != 0)
859 /* Request is not page-aligned. */
861 if (bio_end_sector(bio
) > get_capacity(bio
->bi_bdev
->bd_disk
)) {
862 /* Request beyond end of DCSS segment. */
865 /* verify data transfer direction */
866 if (dev_info
->is_shared
) {
867 switch (dev_info
->segment_type
) {
871 /* cannot write to these segments */
872 if (bio_data_dir(bio
) == WRITE
) {
873 pr_warn("Writing to %s failed because it is a read-only device\n",
874 dev_name(&dev_info
->dev
));
880 index
= (bio
->bi_iter
.bi_sector
>> 3);
881 bio_for_each_segment(bvec
, bio
, iter
) {
882 page_addr
= (unsigned long)
883 page_address(bvec
.bv_page
) + bvec
.bv_offset
;
884 source_addr
= dev_info
->start
+ (index
<<12) + bytes_done
;
885 if (unlikely((page_addr
& 4095) != 0) || (bvec
.bv_len
& 4095) != 0)
888 if (bio_data_dir(bio
) == READ
) {
889 memcpy((void*)page_addr
, (void*)source_addr
,
892 memcpy((void*)source_addr
, (void*)page_addr
,
895 bytes_done
+= bvec
.bv_len
;
898 return BLK_QC_T_NONE
;
901 return BLK_QC_T_NONE
;
905 __dcssblk_direct_access(struct dcssblk_dev_info
*dev_info
, pgoff_t pgoff
,
906 long nr_pages
, void **kaddr
, pfn_t
*pfn
)
908 resource_size_t offset
= pgoff
* PAGE_SIZE
;
909 unsigned long dev_sz
;
911 dev_sz
= dev_info
->end
- dev_info
->start
+ 1;
912 *kaddr
= (void *) dev_info
->start
+ offset
;
913 *pfn
= __pfn_to_pfn_t(PFN_DOWN(dev_info
->start
+ offset
), PFN_DEV
);
915 return (dev_sz
- offset
) / PAGE_SIZE
;
919 dcssblk_blk_direct_access(struct block_device
*bdev
, sector_t secnum
,
920 void **kaddr
, pfn_t
*pfn
, long size
)
922 struct dcssblk_dev_info
*dev_info
;
924 dev_info
= bdev
->bd_disk
->private_data
;
927 return __dcssblk_direct_access(dev_info
, PHYS_PFN(secnum
* 512),
928 PHYS_PFN(size
), kaddr
, pfn
) * PAGE_SIZE
;
932 dcssblk_dax_direct_access(struct dax_device
*dax_dev
, pgoff_t pgoff
,
933 long nr_pages
, void **kaddr
, pfn_t
*pfn
)
935 struct dcssblk_dev_info
*dev_info
= dax_get_private(dax_dev
);
937 return __dcssblk_direct_access(dev_info
, pgoff
, nr_pages
, kaddr
, pfn
);
941 dcssblk_check_params(void)
944 char buf
[DCSSBLK_PARM_LEN
+ 1];
945 struct dcssblk_dev_info
*dev_info
;
947 for (i
= 0; (i
< DCSSBLK_PARM_LEN
) && (dcssblk_segments
[i
] != '\0');
949 for (j
= i
; (j
< DCSSBLK_PARM_LEN
) &&
950 (dcssblk_segments
[j
] != ',') &&
951 (dcssblk_segments
[j
] != '\0') &&
952 (dcssblk_segments
[j
] != '('); j
++)
954 buf
[j
-i
] = dcssblk_segments
[j
];
957 rc
= dcssblk_add_store(dcssblk_root_dev
, NULL
, buf
, j
-i
);
958 if ((rc
>= 0) && (dcssblk_segments
[j
] == '(')) {
959 for (k
= 0; (buf
[k
] != ':') && (buf
[k
] != '\0'); k
++)
960 buf
[k
] = toupper(buf
[k
]);
962 if (!strncmp(&dcssblk_segments
[j
], "(local)", 7)) {
963 down_read(&dcssblk_devices_sem
);
964 dev_info
= dcssblk_get_device_by_name(buf
);
965 up_read(&dcssblk_devices_sem
);
967 dcssblk_shared_store(&dev_info
->dev
,
971 while ((dcssblk_segments
[j
] != ',') &&
972 (dcssblk_segments
[j
] != '\0'))
976 if (dcssblk_segments
[j
] == '\0')
985 static int dcssblk_freeze(struct device
*dev
)
987 struct dcssblk_dev_info
*dev_info
;
990 list_for_each_entry(dev_info
, &dcssblk_devices
, lh
) {
991 switch (dev_info
->segment_type
) {
995 if (!dev_info
->is_shared
)
1006 pr_err("Suspending the system failed because DCSS device %s "
1008 dev_info
->segment_name
);
1012 static int dcssblk_restore(struct device
*dev
)
1014 struct dcssblk_dev_info
*dev_info
;
1015 struct segment_info
*entry
;
1016 unsigned long start
, end
;
1019 list_for_each_entry(dev_info
, &dcssblk_devices
, lh
) {
1020 list_for_each_entry(entry
, &dev_info
->seg_list
, lh
) {
1021 segment_unload(entry
->segment_name
);
1022 rc
= segment_load(entry
->segment_name
, SEGMENT_SHARED
,
1025 // TODO in_use check ?
1026 segment_warning(rc
, entry
->segment_name
);
1029 if (start
!= entry
->start
|| end
!= entry
->end
) {
1030 pr_err("The address range of DCSS %s changed "
1031 "while the system was suspended\n",
1032 entry
->segment_name
);
1039 panic("fatal dcssblk resume error\n");
1042 static int dcssblk_thaw(struct device
*dev
)
1047 static const struct dev_pm_ops dcssblk_pm_ops
= {
1048 .freeze
= dcssblk_freeze
,
1049 .thaw
= dcssblk_thaw
,
1050 .restore
= dcssblk_restore
,
1053 static struct platform_driver dcssblk_pdrv
= {
1056 .pm
= &dcssblk_pm_ops
,
1060 static struct platform_device
*dcssblk_pdev
;
1064 * The init/exit functions.
1069 platform_device_unregister(dcssblk_pdev
);
1070 platform_driver_unregister(&dcssblk_pdrv
);
1071 root_device_unregister(dcssblk_root_dev
);
1072 unregister_blkdev(dcssblk_major
, DCSSBLK_NAME
);
1080 rc
= platform_driver_register(&dcssblk_pdrv
);
1084 dcssblk_pdev
= platform_device_register_simple("dcssblk", -1, NULL
,
1086 if (IS_ERR(dcssblk_pdev
)) {
1087 rc
= PTR_ERR(dcssblk_pdev
);
1091 dcssblk_root_dev
= root_device_register("dcssblk");
1092 if (IS_ERR(dcssblk_root_dev
)) {
1093 rc
= PTR_ERR(dcssblk_root_dev
);
1096 rc
= device_create_file(dcssblk_root_dev
, &dev_attr_add
);
1099 rc
= device_create_file(dcssblk_root_dev
, &dev_attr_remove
);
1102 rc
= register_blkdev(0, DCSSBLK_NAME
);
1106 init_rwsem(&dcssblk_devices_sem
);
1108 dcssblk_check_params();
1112 root_device_unregister(dcssblk_root_dev
);
1114 platform_device_unregister(dcssblk_pdev
);
1116 platform_driver_unregister(&dcssblk_pdrv
);
1120 module_init(dcssblk_init
);
1121 module_exit(dcssblk_exit
);
1123 module_param_string(segments
, dcssblk_segments
, DCSSBLK_PARM_LEN
, 0444);
1124 MODULE_PARM_DESC(segments
, "Name of DCSS segment(s) to be loaded, "
1125 "comma-separated list, names in each set separated "
1126 "by commas are separated by colons, each set contains "
1127 "names of contiguous segments and each name max. 8 chars.\n"
1128 "Adding \"(local)\" to the end of each set equals echoing 0 "
1129 "to /sys/devices/dcssblk/<device name>/shared after loading "
1130 "the contiguous segments - \n"
1131 "e.g. segments=\"mydcss1,mydcss2:mydcss3,mydcss4(local)\"");
1133 MODULE_LICENSE("GPL");